It's interesting you just posted this, as I just came across a similar situation with mine. Beginning in '01, 1500 series Silverados were supposed to have a 1.42" (36mm) front sway bar, regardless of any other configuration. My 2001 truck, made in Canada in 9/00, got the older 1.14" (29mm, but often referred to as 30mm) bar. I replaced my bushings and end links just three days ago with the "1.13" kit, and what a difference it made in the precision of the steering. I did not have a real problem prior, no wandering or constantly having to correct the steering, yet I still noticed a large improvement in stability and precise steering.

Go to ebay and look up item 390510156073. They will ship free, worldwide. The item can also be found on Amazon, and at autozone. BE SURE not to rely on the listng by year and model, as I have seen this item crosslisted for the same years/models right along with the 36mm item. Get the one that closely matches the precise measurement of your sway bar, which I think you will find is 1.14"

One of the first things I do when I get a new Truck is replace the GM Sway bars. My last Av had Hotchkis and my 08 had Hellwig.. Both much better and thicker then GM's so much better handling.. A joy to Drive...:great: